django-mailviews

Class-based email views for the Django framework, including a message previewer.

.. image:: https://travis-ci.org/disqus/django-mailviews.png?branch=master :target: https://travis-ci.org/disqus/django-mailviews

Introduction

Rendering and sending emails in Django can quickly become repetitive and error-prone. By encapsulating message rendering within view classes, you can easily compose messages in a structured and clear manner.

Basic Usage

.. code:: python

from mailviews.messages import TemplatedEmailMessageView

# Subclass the `TemplatedEmailMessageView`, adding the templates you want to render.
class WelcomeMessageView(TemplatedEmailMessageView):
    subject_template_name = 'emails/welcome/subject.txt'
    body_template_name = 'emails/welcome/body.txt'

# Instantiate and send a message.
message = WelcomeMessageView().send(extra_context={
    'user': user,
}, to=(user.email,))

This isn't actually the best pattern for sending messages to a user -- read the notes under "Best Practices" for a better approach.

Using the Preview Site

Registering URLs and Enabling Discovery

* Add ``mailviews`` to your project's ``INSTALLED_APPS`` setting.
* Add the following somewhere within your project's ``ROOT_URLCONF``:

.. code:: python

    from mailviews.previews import autodiscover, site

    autodiscover()

    urlpatterns = [
        url(regex=r'^emails/', view=site.urls),
    ]

The preview index will now be available at the ``emails/`` URL.

Creating Preview Classes
~~~~~~~~~~~~~~~~~~~~~~~~

To create a simple preview, add a ``emails.previews`` submodule within one of your
``INSTALLED_APPS``, and create a new subclass of ``Preview``.

.. code:: python

    from mailviews.previews import Preview, site
    from example.emails.views import WelcomeMessageView

    # Define a new preview class.
    class BasicPreview(Preview):
        message_view = WelcomeMessageView

    # Register the preview class with the preview index.
    site.register(BasicPreview)

You can see more detailed examples within the `test suite <https://github.com/disqus/django-mailviews/blob/master/mailviews/tests/emails/previews.py>`_
or in the code documentation for ``mailviews.previews``.

Customizing Preview Behavior
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can also use Django forms to customize the creation of message previews by
adding a ``form_class`` attribute to your ``Preview`` subclasses. The form must
provide a ``get_message_view_kwargs`` method that returns a the keyword arguments
to be used when constructing the message view instance.

Best Practices
--------------

* Try and avoid using the ``extra_context`` argument when sending emails.
  Instead, create an ``TemplatedEmailMessageView`` subclass whose constructor accepts
  as arguments all of the objects that you require to generate the context and
  send the message. For example, the code shown in "Basic Usage" could written
  instead as the following:

.. code:: python

    from mailviews.messages import TemplatedEmailMessageView

    class WelcomeMessageView(TemplatedEmailMessageView):
        subject_template_name = 'emails/welcome/subject.txt'
        body_template_name = 'emails/welcome/body.txt'

        def __init__(self, user, *args, **kwargs):
            super(WelcomeMessageView, self).__init__(*args, **kwargs)
            self.user = user

        def get_context_data(self, **kwargs):
            context = super(WelcomeMessageView, self).get_context_data(**kwargs)
            context['user'] = self.user
            return context

        def render_to_message(self, *args, **kwargs):
            assert 'to' not in kwargs  # this should only be sent to the user
            kwargs['to'] = (self.user.email,)
            return super(WelcomeMessageView, self).render_to_message(*args, **kwargs)

    # Instantiate and send a message.
    WelcomeMessageView(user).send()

In fact, you might find it helpful to encapsulate the above "message for a user"
pattern into a mixin or subclass that provides a standard abstraction for all
user-related emails. (This is left as an exercise for the reader.)

Testing and Development
-----------------------

Tested on Python 2.6, 2.7 and 3.4 (where supported by Django) and Django
versions 1.3 through 1.8. (For specific versions supported, see the Travis or
Tox build matrices.) To run tests against the entire build matrix locally, run
``make test-matrix`` (or ``tox``, if already installed.)

Development
~~~~~~~~~~~

To install the project in development mode, run:

.. code:: shell

    make develop

This installs dependencies, as well as builds static assets.

Testing
~~~~~~~

To run the test suite against your installed Django version, run:

.. code:: shell

    python -m mailviews.tests

To view an example preview site, you can start a test server by running:

.. code:: shell

    python -m mailviews.tests.manage runserver

Integration with Third-Party Applications
`````````````````````````````````````````

All tests will automatically be run using the Django test runner when you run
the tests for your own projects if you use ``python manage.py test`` and
``mailviews`` is within your ``settings.INSTALLED_APPS``.


Coverage
~~~~~~~~

To generate a Coverage report using coverage.py_, run:

.. code:: shell

    coverage run --source=. -m mailviews.tests


.. _coverage.py: https://pypi.python.org/pypi/coverage/